Author Topic: How can this be..?  (Read 99 times)

zoony

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How can this be..?
« on: Oct 12, 2020, 06:03:51 PM »
  I have a tall bedside lamp with three bulbs and a peculiar phenomenon. Some months ago as I turned the lamp on my computer sound stopped..I use an external sound card which does sometimes glitch for no reason that I've ever been able to fathom so I dismissed it as a coincidence.. but it wasn't. It doesn't happen EVERYtime I switch it on but it's often enough and at the exact moment for it not to be a coincidence.. I know little of electricity or the physics involved so I wondered what the panel might make of it?..
A man said: You can always tell a lady, but you can't tell her much.. (Moliere maybe?)

klondike

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Re: How can this be..?
« Reply #1 on: Oct 12, 2020, 06:42:03 PM »
I can only guess at a dodgy bulb causing a bit of electrical noise on the mains and that causing it somehow. If you have a spare bulb try swapping one out at a time and see if it stops.


zoony

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Re: How can this be..?
« Reply #2 on: Oct 12, 2020, 08:02:14 PM »
Like I said, it doesn't happen every time but I've checked that the bulbs are seated properly..It's not a big deal, I'm just curious as to how/why it happens..
A man said: You can always tell a lady, but you can't tell her much.. (Moliere maybe?)

klondike

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Re: How can this be..?
« Reply #3 on: Oct 12, 2020, 08:37:28 PM »
If they are compact flourescent or LED bulbs there is some circuitry in them. If that is faulty it can generate electrical noise. Try the experiment. If you have no spare then just leave one out.

https://reductionrevolution.com.au/blogs/news-reviews/solutions-to-led-lights-causing-tv-radio-interference


https://interferencetechnology.com/rf-emissions-of-compact-fluorescent-lights/


Such electrical noise can slow your broadband down too.


Diasi

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Re: How can this be..?
« Reply #4 on: Oct 12, 2020, 09:58:08 PM »
LED bulbs are known to cause RF interference & possibly compact flourescents will as well, the cables connecting your speakers can act as an antenna.

You can put ferrite chokes on each end of the speaker & sound card (unless it's a USB plug-in type) cables, which should help whatever the source of the RF interference is.

https://www.amazon.co.uk/Ferrite-Core/s?k=Ferrite+Core
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zoony

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Re: How can this be..?
« Reply #5 on: Oct 12, 2020, 11:08:04 PM »
Once I'd understood what you were talking about it made sense. ;D  They're cheap enough and I'll follow up on that..It's always been prone to cutting out suddenly for no obvious reason..on radio, films, downloads..annoying but infrequent, easily fixed and put-up-withable..
A man said: You can always tell a lady, but you can't tell her much.. (Moliere maybe?)

Traveller

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Re: How can this be..?
« Reply #6 on: Oct 13, 2020, 07:38:42 AM »
Don't have computer problems, but  LED lights give problems with my DAB radio.  Not so bad at home, but is a real problem in the campervan.
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Diasi

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Re: How can this be..?
« Reply #7 on: Oct 13, 2020, 08:22:04 AM »
Don't have computer problems, but  LED lights give problems with my DAB radio.  Not so bad at home, but is a real problem in the campervan.

LED lights are very dependent on the quality of the LED driver & those with poor quality drivers will usually give more interference.

LED lights with poor quality LED drivers can be adversely affected by the capacitive current in lighting circuits & this can often be seen when the bulb glows very sightly when switched off.

A good quality LED driver should be able to cancel out any capacitive current so a quick test is to see if the LED glows when switched off.
« Last Edit: Oct 13, 2020, 08:25:11 AM by Diasi »
Make every day count, each day is precious.

There is nothing more frightful than the ignorant in action.

Apart from the gullible in action.